13- Pre operative Explains Flashcards
1
Q
What is the mechanism of action of heparin?
A
Heparin works by causing the formation of complexes between antithrombin and activated thrombin, as well as factors 7, 9, 10, 11, and 12. This inhibits the clotting cascade and prevents the formation of blood clots.
2
Q
What are the advantages of low molecular weight heparin (LMWH)?
A
Low molecular weight heparin offers several advantages compared to unfractionated heparin. These include better bioavailability, a lower risk of bleeding, a longer half-life, little effect on the activated partial thromboplastin time (APTT) at prophylactic dosages, and a lower risk of heparin-induced thrombocytopenia (HIT).
3
Q
What are some complications associated with heparin use?
A
Complications of heparin use can include bleeding, osteoporosis, heparin-induced thrombocytopenia (HIT) which typically occurs 5-14 days after the first exposure, and anaphylaxis.
4
Q
What are the specific features of propofol as an IV induction agent?
A
Propofol has a rapid onset of anesthesia, but it may cause pain upon IV injection. It is rapidly metabolized with minimal accumulation of metabolites. Additionally, propofol has proven antiemetic (anti-nausea) properties and moderate myocardial depression. It is widely used for maintaining sedation in the intensive care unit (ITU), total IV anesthesia, and for daycase surgery.
4
Q
In surgical patients who may need a rapid return to the operating theater, which type of heparin is preferred?
A
In surgical patients who may require a rapid return to the operating theater, administration of unfractionated heparin is preferred. This is because low molecular weight heparins have a longer duration of action and are more challenging to reverse if necessary.
5
Q
What are the specific features of sodium thiopentone as an IV induction agent?
A
Sodium thiopentone has an extremely rapid onset of action, making it the agent of choice for rapid sequence induction. However, it may cause marked myocardial depression and the buildup of metabolites. It is not suitable for maintenance infusion and has little analgesic effects.
6
Q
What are the specific features of ketamine as an IV induction agent?
A
Ketamine may be used for the induction of anesthesia. It has moderate to strong analgesic properties and produces little myocardial depression, making it suitable for anesthesia in individuals who are hemodynamically unstable. However, ketamine may induce a state of dissociative anesthesia, which can result in nightmares.
7
Q
What are the specific features of etomidate as an IV induction agent?
A
Etomidate has a favorable cardiac safety profile with minimal hemodynamic instability. It does not possess analgesic properties. However, it is unsuitable for maintaining sedation as prolonged or even brief use may lead to adrenal suppression. Post-operative vomiting is common with the use of etomidate.
8
Q
What are the possible causes of aortic stenosis?
A
Aortic stenosis can occur as a result of rheumatic fever, aging, and calcific changes. In congenital cases, it may occur earlier due to the calcification of a bicuspid aortic valve, which affects around 1-2% of the population.
9
Q
What are the symptoms of aortic stenosis?
A
Symptoms of aortic stenosis may include exertional angina (chest pain during physical activity) and syncope (fainting).
10
Q
What is the preferred investigation for diagnosing aortic stenosis?
A
When aortic stenosis is suspected, trans thoracic echocardiography is the investigation of choice for evaluation and diagnosis.
11
Q
What are the severity classifications for aortic stenosis based on mean gradient and aortic valve area?
A
The severity of aortic stenosis can be classified as mild (mean gradient <25 mmHg, aortic valve area >1.5 cm²), moderate (mean gradient 25-40 mmHg, aortic valve area 1.0-1.5 cm²), or severe (mean gradient >40 mmHg, aortic valve area <1 cm²).
12
Q
What are the treatment options for aortic stenosis?
A
The treatment for aortic stenosis typically involves either transcatheter or open aortic valve replacement, depending on the individual’s condition and medical evaluation.
13
Q
What are the recommended preparations for elective surgery?
A
For elective surgery, it is important to consider a pre-admission clinic to address any medical issues. Blood tests including FBC, U+E, LFT’s, clotting, and Group and Save should be conducted. A urine analysis, pregnancy test, and sickle cell test may also be necessary. Additional tests such as ECG and chest x-ray should be performed based on the proposed procedure and patient fitness. Assessing risk factors for deep vein thrombosis and formulating a plan for thromboprophylaxis is crucial.
14
Q
How should diabetic patients be prepared for surgery?
A
Diabetic patients have a higher risk of complications, especially if their diabetes is poorly controlled. Patients with diet or tablet-controlled diabetes may have their medication omitted, with regular blood glucose level checks. Poorly controlled or insulin-dependent diabetics may require an intravenous sliding scale. Potassium supplementation should also be given. Diabetic cases should be prioritized for surgery.
15
Q
What preparations are necessary for emergency surgery?
A
For emergency surgery, it is important to stabilize and resuscitate the patient as needed. Antibiotics should be considered if required, and their administration should be determined. If major procedures are planned, particularly when coagulopathies are present or anticipated, the blood bank should be informed. Consent and informing relatives should not be forgotten.
16
Q
Are there any special preparations for specific procedures?
A
Yes, some procedures require special preparations. For thyroid surgery, a vocal cord check is necessary. For parathyroid surgery, methylene blue may be considered to identify the gland. Sentinel node biopsy may require a radioactive marker or patent blue dye. Surgery involving the thoracic duct may require the administration of cream. Pheochromocytoma surgery will need alpha and beta blockade. Surgery for carcinoid tumors may require covering with octreotide. Colorectal cases may require bowel preparation, especially for left-sided surgery. Thyrotoxicosis may require Lugol’s iodine or medical therapy.
17
Q
What are the main stages of wound healing?
A
The main stages of wound healing include haemostasis, inflammation, regeneration, and remodeling.
18
Q
What happens during the haemostasis stage of wound healing?
A
During the haemostasis stage, which occurs minutes to hours following an injury, vasospasm in adjacent vessels, platelet plug formation, and the generation of a fibrin-rich clot take place.
19
Q
What occurs during the inflammation stage of wound healing?
A
The inflammation stage typically occurs from day 1 to day 5 after an injury. Neutrophils migrate into the wound, and growth factors such as basic fibroblast growth factor and vascular endothelial growth factor are released. Fibroblasts replicate and migrate into the wound, while macrophages and fibroblasts facilitate matrix regeneration and clot substitution.
20
Q
What happens during the regeneration stage of wound healing?
A
The regeneration stage typically occurs from day 7 to day 56. Platelet-derived growth factor and transformation growth factors stimulate the activity of fibroblasts and epithelial cells. Fibroblasts produce a collagen network, angiogenesis occurs, and the wound begins to resemble granulation tissue.
21
Q
What occurs during the remodeling stage of wound healing?
A
The remodeling stage takes place from 6 weeks to 1 year after an injury. Fibroblasts become differentiated (myofibroblasts) and aid in wound contraction. Collagen fibers are remodeled, microvessels regress, and a pale scar forms.
22
Q
What are some factors that can impair the wound healing process?
A
Conditions such as vascular disease, shock, sepsis, and jaundice can impair microvascular flow and negatively impact wound healing. Additionally, certain drugs like nonsteroidal anti-inflammatory drugs (NSAIDs), steroids, immunosuppressive agents, and anti-neoplastic drugs can impair wound healing.
23
Q
What are the potential problems with scars?
A
Hypertrophic scars are characterized by excessive amounts of collagen within the scar. They may contain nodules and can develop contractures. Keloid scars also have excessive collagen, but they extend beyond the boundaries of the original injury and can occur even after trivial injury. Keloid scars do not regress over time and may recur after removal.
24
What is the difference between delayed primary closure and secondary closure?
Delayed primary closure refers to anatomically precise closure that is delayed for a few days but done before granulation tissue becomes macroscopically visible. Secondary closure can refer to spontaneous closure or surgical closure after granulation tissue has formed.
25
What are some important principles to appreciate regarding surgical complications?
Some important principles to appreciate regarding surgical complications are the anatomical principles that underpin complications, the physiological and biochemical derangements that occur, the most appropriate diagnostic modalities to utilize, and the principles that underpin their management.
26
What are some ways to avoid complications in surgery?
Some points to hopefully avert complications in surgery include following the World Health Organisation checklist prior to all operations, using prophylactic antibiotics at the right dose, right drug, and right time, assessing the risk of deep vein thrombosis/pulmonary embolism and ensuring adequate prophylaxis, marking the site of surgery, using tourniquets with caution and respecting underlying structures, avoiding using adrenaline-containing solutions and monopolar diathermy in situations where end arteries are present, handling tissues with care to prevent devitalized tissue as a nidus for infection, and being cautious of potential coupling injuries when using diathermy during laparoscopic surgery.
27
Why is understanding the anatomy of a surgical field important?
Understanding the anatomy of a surgical field is important because it allows for the appreciation of local and systemic complications that may occur. For example, knowledge of specific nerves in a region can help prevent nerve injuries during surgery.
28
Can you provide examples of nerves that may be at risk of injury during surgery?
Some examples of nerves that may be at risk of injury during surgery include the accessory nerve during posterior triangle lymph node biopsy, the sciatic nerve during a posterior approach to the hip, the common peroneal nerve when the legs are in the Lloyd Davies position, the long thoracic nerve during axillary node clearance, the pelvic autonomic nerves during pelvic cancer surgery, the recurrent laryngeal nerves during thyroid surgery, and the hypoglossal nerve during carotid endarterectomy.
29
What are some structures that may be at risk of injury during surgery?
Some structures that may be at risk of injury during surgery include the thoracic duct during thoracic surgery (e.g., pneumonectomy, esophagectomy), the parathyroid glands during difficult thyroid surgery, the ureters during colonic resections or gynecological surgery, the bowel with the use of a Verres Needle to establish pneumoperitoneum, the bile duct with failure to delineate Calot's triangle carefully and careless use of diathermy, the facial nerve during parotidectomy, the tail of the pancreas when ligating the splenic hilum, the testicular vessels during re-do open hernia surgery, and the hepatic veins during liver mobilization.
30
What are some physiological and biochemical issues that can lead to complications?
Some physiological and biochemical issues that can lead to complications include susceptibility to hypokalemia (low potassium levels) in cardiac patients following cardiac surgery, neurosurgical electrolyte disturbances such as syndrome of inappropriate antidiuretic hormone secretion (SIADH) causing hyponatremia (low sodium levels) following cranial surgery, ileus (intestinal paralysis) following gastrointestinal surgery resulting in fluid sequestration and loss of electrolytes, pulmonary edema (fluid accumulation in the lungs) following pneumonectomy (surgical removal of a lung) due to loss of lung volume making patients sensitive to fluid overload, anastomotic leak leading to generalized sepsis causing mediastinitis (inflammation of the space between the lungs) or peritonitis (inflammation of the abdominal lining) depending on the site of the leak, and myocardial infarction (heart attack) that may follow any type of surgery and can compromise grafts and decrease cardiac output.
31
What are some baseline investigations that are often helpful in acutely unwell surgical patients?
Some baseline investigations that are often helpful in acutely unwell surgical patients include a full blood count, urea and electrolytes, C-reactive protein (trend rather than absolute value), serum calcium, liver function tests, clotting (should be repeated if ongoing bleeding is present), arterial blood gases, ECG (electrocardiogram) with cardiac enzymes if myocardial infarction is suspected, chest x-ray to identify collapse or consolidation in the lungs, and urine analysis for urinary tract infection. These investigations can often identify the most common complications.
32
What are some special tests that can be used to identify specific complications?
Some special tests that can be used to identify specific complications include CT scanning for the identification of intra-abdominal abscesses, Doppler ultrasound of leg veins for the identification of deep vein thrombosis, CTPA (computed tomography pulmonary angiography) for pulmonary embolism, sending peritoneal fluid for urea and electrolyte analysis if ureteric injury is suspected, sending peritoneal fluid for amylase analysis if pancreatic injury is suspected, and echocardiogram if pericardial effusion (fluid around the heart) is suspected post cardiac surgery and no pleural window was made.
33
What is the guiding principle for managing complications?
The guiding principle for managing complications should be safe and timely intervention. Patients should be stabilized, and if an operation needs to occur alongside resuscitation, it should generally be a damage limitation procedure rather than definitive surgery. Definitive surgery can be more safely undertaken in a stable patient the following day.
34
What is the recommended approach for laparotomies in cases of bleeding?
As a general rule, laparotomies for bleeding should follow the core principle of quadrant packing and subsequent pack removal rather than plunging large clamps into pools of blood. The latter approach often worsens the situation and can result in significant visceral injury, especially when done by inexperienced individuals. If packing effectively controls the situation, it is entirely acceptable to leave packs in place and return the patient to the intensive care unit (ICU) for pack removal the following day.
35
What are the indications for IV fluids in children?
The indications for IV fluids in children include resuscitation and circulatory support, replacing ongoing fluid losses, providing maintenance fluids for children who cannot take oral fluids, and correcting electrolyte disturbances.
36
Which fluids should be avoided in children outside the neonatal period?
In children outside the neonatal period, saline/glucose solutions should be avoided. The greatest risk is associated with saline 0.18%/glucose 4% solutions. The report suggests that 0.45% saline/5% glucose may be used, but preference should be given to isotonic solutions and there are few indications for this solution as well.
37
Which fluids are recommended for use in paediatric fluid management?
The recommended fluids for paediatric fluid management include 0.9% saline, 5% glucose (but only with saline for maintenance and not to replace losses), and Hartmann's solution.
38
What should be considered when adding potassium to maintenance fluids?
Potassium should be added to maintenance fluids based on the patient's plasma potassium levels, which should be monitored.
39
What type of fluid should neonates receive during surgery?
Neonates should receive glucose 10% during surgery.
40
What type of fluid should other children receive during surgery?
Other children should receive isotonic crystalloid during surgery.
41
What is the recommended rate of glucose administration for neonates?
Neonates usually require glucose 10% at a rate of 60ml per kilogram of body weight per day.
41
What are the recommended water and electrolyte requirements for maintenance fluids based on the child's weight?
For maintenance fluids, the water requirement per kilogram of body weight is 100ml for the first 10kg, 50ml for the second 10kg, and 20ml for subsequent kilograms. The sodium requirement per kilogram of body weight is 2-4 mmol for the first 10kg, 1-2 mmol for the second 10kg, and 0.5-1.0 mmol for subsequent kilograms. The potassium requirement per kilogram of body weight is 1.5-2.5 mmol for the first 10kg, 0.5-1.5 mmol for the second 10kg, and 0.2-0.7 mmol for subsequent kilograms.
42
What is the technique used for splenectomy in cases of trauma?
In cases of trauma, splenectomy is performed under general anesthesia. A long midline incision is made, and if time permits, a self-retaining retractor (e.g., Balfour or omnitract) is inserted. Since there is usually a large amount of free blood present, all four quadrants of the abdomen are packed. The viability of the spleen is assessed after removing the packs, and if there are hilar injuries or extensive parenchymal lacerations, splenectomy is usually required. The short gastric vessels are divided and ligated, followed by clamping and ligating the splenic artery and vein. Care should be taken not to damage the tail of the pancreas, as this may require formal removal and closure of the pancreatic duct. The abdomen is washed out, and a tube drain is placed in the splenic bed. Some surgeons choose to implant a portion of the spleen into the omentum, but this is a personal choice. Postoperatively, the patient will require prophylactic penicillin V and pneumococcal vaccine.
43
What are the indications for splenectomy?
The indications for splenectomy include trauma (with 1/4 being iatrogenic), spontaneous rupture due to EBV, hypersplenism (associated with conditions like hereditary spherocytosis or elliptocytosis), malignancy (such as lymphoma or leukemia), and conditions like splenic cysts, hydatid cysts, and splenic abscesses.
44
How is elective splenectomy different from emergency splenectomy?
Elective splenectomy is different from emergency splenectomy in terms of the operation setting and the size of the spleen. Elective splenectomies are often performed laparoscopically and the spleen is usually large, sometimes massive. The spleen is typically macerated inside a specimen bag to facilitate extraction.
45
What are the complications associated with splenectomy?
Complications of splenectomy include early hemorrhage (which can occur from short gastrics or splenic hilar vessels), pancreatic fistula (resulting from iatrogenic damage to the pancreatic tail), and thrombocytosis (for which prophylactic aspirin may be given). There is also an increased risk of post-splenectomy sepsis, particularly from encapsulated bacteria such as Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis.
46
What is post-splenectomy sepsis typically associated with?
Post-splenectomy sepsis typically occurs with encapsulated organisms. Opsonization occurs, but these organisms are not recognized effectively by the immune system.
46
What changes occur in the blood following splenectomy?
Following splenectomy, platelet levels rise first, so in cases of ITP, platelets should be given after clamping the splenic artery. The blood film will also change over the following weeks, with the appearance of Howell-Jolly bodies, target cells, and Pappenheimer bodies. There is an increased risk of post-splenectomy sepsis, so prophylactic antibiotics and pneumococcal vaccine should be administered.
47
What are the nutrition options available for surgical patients?
The nutrition options for surgical patients include oral intake, nasogastric feeding, nasojejunal feeding, feeding jejunostomy, percutaneous endoscopic gastrostomy, and total parenteral nutrition.
48
What is the easiest option for nutrition in surgical patients?
Oral intake is the easiest option for nutrition in surgical patients. It may be supplemented by calorie-rich dietary supplements. However, it may be contraindicated following certain procedures.
49
What is nasogastric feeding and how is it administered?
Nasogastric feeding is usually administered via a fine bore nasogastric feeding tube. Complications of nasogastric feeding include aspiration of feed or misplaced tube. It may be safe to use in patients with impaired swallowing. However, it is often contraindicated following head injury due to the risks associated with tube insertion.
50
What is nasojejunal feeding and when is it typically used?
Nasojejunal feeding is a nutrition option that avoids problems of feed pooling in the stomach and the risk of aspiration. The insertion of the feeding tube is more technically complicated, and it is easiest if done intraoperatively. Nasojejunal feeding is safe to use following oesophagogastric surgery.
51
What is feeding jejunostomy and when is it used?
Feeding jejunostomy is a surgically sited feeding tube that may be used for long-term feeding. It has a low risk of aspiration and is thus safe for long-term feeding following upper gastrointestinal surgery. The main risks associated with feeding jejunostomy are tube displacement and peritubal leakage immediately following insertion, which carries a risk of peritonitis.
52
What is the mechanism of action of warfarin?
Warfarin is an oral anticoagulant that inhibits the reduction of vitamin K to its active hydroquinone form. This, in turn, acts as a cofactor in the formation of clotting factors II, VII, IX, and X, as well as protein C.
52
What is percutaneous endoscopic gastrostomy (PEG) and what are its risks?
Percutaneous endoscopic gastrostomy (PEG) is a nutrition option that involves combined endoscopic and percutaneous tube insertion. However, it may not be technically possible in patients who cannot undergo successful endoscopy. Risks of PEG include aspiration and leakage at the insertion site.
53
What is total parenteral nutrition (TPN) and when is it used?
Total parenteral nutrition (TPN) is the definitive option for patients in whom enteral feeding is contraindicated. It requires individualized prescribing and monitoring and should be administered via a central vein as it is strongly phlebitic. Long-term use of TPN is associated with fatty liver and deranged liver function tests (LFTs).
54
What are some factors that may potentiate the effects of warfarin?
Factors that may potentiate the effects of warfarin include liver disease, P450 enzyme inhibitors such as amiodarone and ciprofloxacin, cranberry juice, drugs that displace warfarin from plasma albumin (e.g., NSAIDs), and drugs that inhibit platelet function (e.g., NSAIDs).
55
What are the side-effects of warfarin?
The side-effects of warfarin include hemorrhage, teratogenic effects, and skin necrosis. Skin necrosis can occur when warfarin is first started due to reduced biosynthesis of protein C, resulting in a temporary procoagulant state. This is normally avoided by concurrent administration of heparin. Thrombosis may occur in venules, leading to skin necrosis.
56
What is the World Health Organisation (WHO) Analgesic Ladder?
The World Health Organisation (WHO) Analgesic Ladder is a stepwise approach for the management of pain. It begins with the use of peripherally acting drugs such as paracetamol or non-steroidal anti-inflammatory drugs (NSAIDs). If pain control is not achieved, weak opioid drugs like codeine or dextropropoxyphene are introduced, along with agents to control side effects. The final step is the use of strong opioid drugs like morphine. Peripherally acting drugs and centrally-acting opioids can be given together for additive analgesic effects.
57
What is the World Federation of Societies of Anaesthesiologists (WFSA) Analgesic Ladder?
The World Federation of Societies of Anaesthesiologists (WFSA) Analgesic Ladder is a similar approach for the management of acute pain. Initially, severe pain may be controlled with strong analgesics in combination with local anesthetic blocks and peripherally acting drugs. The second step involves restoring the use of the oral route for analgesia, using combinations of peripherally acting agents and weak opioids. The final step is when pain can be controlled by peripherally acting agents alone.
58
What are some methods for providing local anesthesia and pain relief?
Methods for providing local anesthesia and pain relief include infiltration of a wound with a long-acting local anesthetic like bupivacaine, blockade of plexuses or peripheral nerves, spinal anesthesia, epidural anesthesia, transversus abdominal plane block (TAP), and patient-controlled analgesia (PCA).
Strong Opioids, Weak opioids, Paracetamol, NSAIDs
59
What are the advantages and disadvantages of spinal anesthesia?
Advantages of spinal anesthesia include excellent analgesia for surgery in the lower half of the body and prolonged pain relief after the operation. However, side effects can include hypotension, sensory and motor block, nausea, and urinary retention.
60
What are the advantages and disadvantages of epidural anesthesia?
Advantages of epidural anesthesia include excellent analgesia and prevention of postoperative respiratory compromise. However, disadvantages include confinement to bed, especially with a motor block, and the need for an indwelling urinary catheter. Epidurals are contraindicated in coagulopathies.
61
What is a transversus abdominal plane block (TAP)?
A transversus abdominal plane block (TAP) is a technique where an ultrasound is used to identify the correct muscle plane, and local anesthetic (usually bupivacaine) is injected. This blocks many of the spinal nerves and provides a wide field of blockade. TAP is preferred for extensive laparoscopic abdominal procedures as it does not require the placement of indwelling devices and does not cause postoperative motor impairment. However, its duration of action is limited to the half-life of the local anesthetic chosen.
62
What are the characteristics of pethidine?
Pethidine is a synthetic opioid with similar actions to morphine. It has a short half-life and similar bioavailability and clearance. It has a short duration of action and may need to be given hourly. Pethidine has a toxic metabolite called norpethidine, which can accumulate in renal failure or with frequent and prolonged doses, leading to muscle twitching and convulsions. Extreme caution is advised if pethidine is used over a prolonged period or in patients with renal failure.
62
What is patient-controlled analgesia (PCA)?
Patient-controlled analgesia (PCA) is a method where patients administer their own intravenous analgesia using a small microprocessor-controlled pump. The dose can be titrated to their own desired level of pain relief. Morphine is commonly used for PCA.
63
What are the characteristics of morphine?
Morphine has a short half-life and poor bioavailability. It is metabolized in the liver and its clearance is reduced in patients with liver disease, the elderly, and the debilitated. Side effects include nausea, vomiting, constipation, and respiratory depression. Tolerance may occur with repeated dosage.
64
What are the characteristics of NSAIDs?
NSAIDs have analgesic and anti-inflammatory actions. They work by inhibiting prostaglandin synthesis. All NSAIDs work in the same way, so there is no point in giving more than one at a time. They are more useful for superficial pain arising from the skin, buccal mucosa, joint surfaces, and bone. They have relative contraindications, including a history of peptic ulceration, gastrointestinal bleeding or bleeding diathesis, operations associated with high blood loss, asthma, moderate to severe renal impairment, dehydration, and any history of hypersensitivity to NSAIDs or aspirin.
65
What are the characteristics of paracetamol?
Paracetamol inhibits prostaglandin synthesis and has analgesic and antipyretic properties. It has little anti-inflammatory effect. It is well absorbed orally and metabolized almost entirely in the liver. It is widely used for the treatment of minor pain but can cause hepatotoxicity in overdose.
66
What are the first-line medications for neuropathic pain according to the National Institute of Clinical Excellence (UK) guidelines?
The first-line medications for neuropathic pain are amitriptyline (or imipramine if cannot tolerate) or pregabalin.
67
What are the second-line medications for neuropathic pain according to the National Institute of Clinical Excellence (UK) guidelines?
The second-line medications for neuropathic pain are amitriptyline AND pregabalin.
68
When should a pain specialist be referred to for neuropathic pain management?
If first and second-line medications are ineffective or if the pain is diabetic neuropathic pain, a pain specialist should be referred to. In the interim, tramadol can be given, but morphine should be avoided.
69
What medication is recommended for diabetic neuropathic pain?
For diabetic neuropathic pain, duloxetine is recommended.
70
What is the procedure for transurethral prostatectomy?
Transurethral prostatectomy involves the insertion of a resectoscope via the penile urethra. The bladder and prostate are irrigated, and strips of prostatic tissue are removed using diathermy.
71
What are the indications for surgery in patients with benign prostatic hyperplasia (BPH)?
The indications for surgery in patients with BPH include refractory urinary retention, recurrent urinary tract infections due to prostatic hypertrophy, recurrent gross hematuria, renal insufficiency secondary to bladder outlet obstruction, permanently damaged or weakened bladders, and large bladder diverticula that do not empty well due to an enlarged prostate.
72
What are the complications of transurethral prostatectomy?
The complications of transurethral prostatectomy include hemorrhage, urosepsis, retrograde ejaculation, and electrolyte disturbances from the irrigation fluids used during surgery.
73
What are the risk factors for increased morbidity following transurethral prostatectomy (TURP)?
The risk factors for increased morbidity following TURP are glands larger than 45g, operating time exceeding 90 minutes, and acute urinary retention as the presenting feature.
74
What are the causes of hyperthyroidism?
The causes of hyperthyroidism include diffuse toxic goiter (Graves Disease), toxic nodular goiter, toxic nodule, and rare causes.
75
What is Graves disease?
Graves disease is characterized by a diffuse vascular goiter and is most common in younger females. It may be associated with eye signs. Symptoms of hyperthyroidism predominate in this condition.
76
What is toxic nodular goiter?
Toxic nodular goiter is characterized by the presence of a goiter for a long period of time before the development of clinical symptoms. In some cases, the hyperthyroidism is caused by the internodular tissue rather than the nodules.
77
What is a toxic nodule?
A toxic nodule is an overactive, autonomously functioning nodule. It may occur as part of generalized nodularity or be a true toxic adenoma. TSH levels are usually low due to the negative feedback effect of the autonomously functioning thyroid tissue.
78
What are the signs and symptoms of hyperthyroidism?
The signs and symptoms of hyperthyroidism include lethargy, tachycardia, agitation, heat intolerance, weight loss, excessive appetite, palpitations, exophthalmos, hot and moist palms, thyroid goiter and bruit, and lid lag/retraction.
79
What is the most sensitive test for diagnosing hyperthyroidism?
The most sensitive test for diagnosing hyperthyroidism is plasma T3, which is typically raised.
80
What is the first-line treatment for Graves disease?
The first-line treatment for Graves disease is usually medical, and the block and replace regime is the favored option. This involves administering higher doses of carbimazole and orally administering thyroxine. Patients are maintained on this regime for 6 to 12 months, and attempts are made to wean off medication.
81
What are the treatment options for Graves disease if relapse occurs after initial treatment?
If relapse occurs after initial treatment for Graves disease, the options include ongoing medical therapy, radioiodine, or surgery.
82
What is endoscopy?
Endoscopy is a procedure that allows for the internal visualization of the viscera. It is commonly used for procedures such as gastroscopy, colonoscopy, cystoscopy, ERCP, and bronchoscopy. Unlike laparoscopy, endoscopy does not typically involve the inspection of a visceral cavity.
83
What are the components of most endoscopes?
Most endoscopes are flexible instruments with three channels and a video chip with an illumination source at the end. The channels are used for suction, irrigation, and instrumentation. The flexible instruments also have a control stack with wheels that allow for manipulation of the instrument's tip.
84
What are some considerations for performing endoscopies?
Endoscopies should be performed in dedicated units with appropriately trained staff and full resuscitation facilities available. Some procedures may require patient sedation, while others may not.
85
What is the preparation for endoscopy?
The preparation for endoscopy depends on the organ to be examined. For ERCP, clotting, antibiotics, and Vitamin K may be necessary if the patient is jaundiced. For diagnostic OGD (esophagogastroduodenoscopy), the patient should be nil by mouth for 6 hours. For flexible sigmoidoscopy, a phosphate enema should be administered 30 minutes before the procedure. For colonoscopy, U+E (urea and electrolyte) levels should be checked, and if normal, oral purgatives such as picolax may be prescribed.
86
What are the different routes for establishing venous access?
The different routes for establishing venous access include peripheral venous cannula, central lines, intraosseous access, tunneled lines, and peripherally inserted central cannula (PICC) lines.
87
What are the advantages and disadvantages of peripheral venous cannula?
Peripheral venous cannulae are easy to insert with minimal morbidity and allow for rapid fluid infusions. However, they are unsuitable for administering vasoactive drugs and irritant drugs, such as TPN, except in the very short term setting. Infections at peripheral sites can also occur.
88
What are the considerations for central lines?
Insertion of central lines is more difficult and often requires the use of ultrasound. Coagulopathies can lead to hemorrhage from iatrogenic arterial injury. While femoral lines are easier to insert, they are prone to high infection rates. The internal jugular route is preferred. Central lines have multiple lumens for administering multiple infusions, but the lumens are relatively narrow, limiting the rate of infusion.
89
What is intraosseous access?
Intraosseous access involves accessing the marrow cavity and circulatory system through the anteromedial aspect of the proximal tibia. Although traditionally used in pediatric practice, it can also be used in adults. Intraosseous access allows for the infusion of a wide range of fluids.
90
What are tunneled lines?
Tunneled lines, such as Groshong and Hickman lines, are devices commonly used for patients with long-term therapeutic requirements. They are inserted into the internal jugular vein using ultrasound guidance and then tunneled under the skin. A cuff helps anchor the device into the tissues. These lines can be linked to injection ports located under the skin, which is especially popular in pediatric practice.
91
What are peripherally inserted central cannula (PICC) lines?
PICC lines are methods for establishing central venous access. They are inserted peripherally, making them less prone to major complications related to device insertion compared to conventional central lines.
92
What is the risk of untreated deep vein thrombosis in surgical patients?
Untreated deep vein thrombosis in surgical patients can progress and result in pulmonary embolism.
93
What are the factors that increase the risk of deep vein thrombosis in surgical patients?
The following factors increase the risk of deep vein thrombosis in surgical patients: surgery lasting more than 90 minutes (or more than 60 minutes involving the lower limbs or pelvis), acute admissions with an inflammatory process involving the abdominal cavity, expected significant reduction in mobility, age over 60 years, known malignancy, thrombophilia, previous thrombosis, BMI over 30, taking hormone replacement therapy or the contraceptive pill, varicose veins with phlebitis.
94
What are some mechanical thromboprophylaxis methods?
Mechanical thromboprophylaxis methods include early ambulation after surgery, compression stockings (contraindicated in peripheral arterial disease), intermittent pneumatic compression devices, and foot impulse devices.
95
What are some therapeutic agents used for thromboprophylaxis or treatment of thromboembolic events?
Some therapeutic agents used for thromboprophylaxis or treatment of thromboembolic events include low molecular weight heparin (given as once-daily subcutaneous injection), unfractionated heparin (administered intravenously), and dabigatran (orally administered direct thrombin inhibitor).
96
How does low molecular weight heparin work?
Low molecular weight heparin binds to antithrombin, causing inhibition of factor Xa.
97
How does unfractionated heparin work?
Unfractionated heparin binds to antithrombin III, affecting thrombin and factor Xa. It is administered intravenously and has a rapid onset and a quick decline in therapeutic effects upon stopping the infusion. Its activity is measured using the APTT (activated partial thromboplastin time).
98
What is dabigatran and its use?
Dabigatran is an orally administered direct thrombin inhibitor. It is used for prophylaxis in hip and knee surgery. It does not require therapeutic monitoring. However, it should not be used in patients at risk of active bleeding or imminent likelihood of surgery. It can be reversed using Idarucizumab.
99
What are the different manifestations of thyroid disease?
Patients with thyroid disease can present with various manifestations. They can be classified based on whether they are euthyroid (normal thyroid function) or have clinical signs of thyroid dysfunction. It is also important to establish whether they have a thyroid mass or not.
100
What is the recommended assessment for thyroid disease?
The assessment for thyroid disease includes obtaining a thorough history, conducting a physical examination, and performing an ultrasound. If a nodule is identified, it should be sampled through an image-guided fine needle aspiration. Radionucleotide scanning is of limited use.
101
What are the different types of thyroid tumors?
Thyroid tumors can include papillary carcinoma, follicular carcinoma, anaplastic carcinoma, medullary carcinoma, and lymphomas.
102
What is the management approach for multinodular goitre?
If a patient with multinodular goitre is euthyroid, asymptomatic, and no discrete nodules are seen, they can be reassured. However, if they have compressive symptoms, surgery (total thyroidectomy) is required. Partial resections in the past have resulted in recurrent disease, necessitating difficult revisional resections.
103
What are the potential complications following thyroid surgery?
Complications following thyroid surgery can include anatomical issues such as recurrent laryngeal nerve damage, bleeding (which can lead to respiratory compromise due to laryngeal edema in the confined space), and damage to the parathyroid glands resulting in hypocalcemia.
103
How are patients with endocrine dysfunction managed?
Patients with endocrine dysfunction are initially managed by physicians. In cases of Graves disease that fails with medical management or in patients who prefer not to be irradiated (e.g. pregnant women), surgery may be offered alongside radioiodine. Patients with hypothyroidism do not typically undergo thyroidectomy. Patients with Hashimoto's thyroiditis may inadvertently be offered resections during the early phase, but with time, the toxic phase passes and they can be managed with thyroxine.
104
What are the ECG changes associated with hypercalcemia?
ECG changes associated with hypercalcemia include shortening of the QTc interval.
104
What factors affect free calcium levels in the body?
Free calcium levels in the body are affected by pH (increased in acidosis) and plasma albumin concentration.
105
What is the recommended management for hypercalcemia?
The management of hypercalcemia involves ensuring airway, breathing, and circulation. Intravenous fluid resuscitation with 3-6L of 0.9% normal saline in 24 hours is recommended. Concurrent administration of calcitonin can also help lower calcium levels. Medical therapy, such as bisphosphonates and analogues of pyrophosphate, may be used if corrected calcium levels are greater than 3.0 mmol/L.
105
When is urgent management indicated for hypercalcemia?
Urgent management is indicated for hypercalcemia in the following situations: calcium levels greater than 3.5 mmol/L, reduced consciousness, severe abdominal pain, and pre-renal failure.
106
What is the mechanism of action of bisphosphonates?
Bisphosphonates prevent osteoclast attachment to bone matrix and interfere with osteoclast activity, thereby inhibiting bone resorption.
106
What are the agents used in medical therapy for hypercalcemia?
The agents used in medical therapy for hypercalcemia include IV Pamidronate (most potent agent, may cause pyrexia and leucopenia), IV Zoledronate (response lasts 30 days, used for malignancy-associated hypercalcemia), Calcitonin (quickest onset of action but short duration, given with a second agent), and Prednisolone (may be given in hypercalcemia related to sarcoidosis, myeloma, or vitamin D intoxication).
107
When should enteral feeding be considered for patients?
Enteral feeding should be considered for patients who are malnourished or at risk of malnutrition and have unsafe or inadequate oral intake despite having a functional gastrointestinal (GI) tract.
108
What is the preferred route for enteral feeding?
Gastric feeding is the preferred route unless there is upper GI dysfunction. In such cases, a duodenal or jejunal tube should be used.
109
How can the placement of a nasogastric (NG) tube be checked?
The placement of an NG tube should be checked using aspiration and pH testing. For post-pyloric tubes, an abdominal X-ray should be done to confirm placement.
109
What should be considered if gastric feeding is required for more than 4 weeks?
If gastric feeding is required for more than 4 weeks, long-term gastrostomy should be considered.
110
What are the options for enteral feeding into the stomach?
Enteral feeding into the stomach can be done either through bolus feeding or continuous feeding.
111
How should enteral feeding be managed in intensive care unit (ITU) patients?
ITU patients should have continuous feeding for 16-24 hours, with 24 hours if they are on insulin. Motility agents can be considered for delayed gastric emptying. If this is ineffective, post-pyloric feeding or parenteral feeding can be tried.
112
When can a percutaneous endoscopic gastrostomy (PEG) tube be used?
A PEG tube can be used 4 hours after insertion, but it should not be removed until more than 2 weeks after insertion.
113
In what cases should pre-operative enteral feeding be considered for surgical patients?
Pre-operative enteral feeding should be considered for surgical patients who are malnourished, have unsafe swallowing or inadequate oral intake, and have a functional GI tract.
114
How can patients be identified as malnourished or at risk of malnutrition?
Patients can be identified as malnourished if they have a BMI < 18.5 kg/m² or unintentional weight loss of > 10% over 3-6 months. Patients are considered at risk of malnutrition if they have a BMI < 20 kg/m² and unintentional weight loss of > 5% over 3-6 months, have eaten nothing or very little for > 5 days and are likely to continue with poor intake for another 5 days, have poor absorptive capacity, high nutrient losses, or high metabolism.
115
What are the possible causes of post-operative pyrexia?
Possible causes of post-operative pyrexia include anastomotic leak, wound infection, atelectasis, central line sepsis, and urinary tract infection.
116
What are the features of an anastomotic leak?
An anastomotic leak may present with swinging pyrexia, ileus, increasing abdominal pain, and raised inflammatory markers.
117
What are the signs of a wound infection?
A wound infection may present with evidence of superficial erythema, discharge of pus, increasing pain, and, in severe cases, wound dehiscence. Mild pyrexia is usually present, unless there is a major or deep-seated wound infection. Inflammatory markers are also raised.
118
What is atelectasis and how does it relate to post-operative pyrexia?
Atelectasis is a complication that often occurs after abdominal surgery, particularly midline laparotomies. It is characterized by mild and non-swinging pyrexia. Most patients will have chest signs on examination, and inflammatory markers may be raised.
119
What is central line sepsis?
Central line sepsis refers to an infection that occurs in patients with complex venous access. It may present with marked pyrexia and evidence of erythema at the access site. Diagnosis is made by blood culture from the line, removal of the line, and subsequent tip culture. Groin lines and those used for total parenteral nutrition (TPN) are commonly affected.
120
How common is urinary tract infection in surgical patients?
Urinary tract infections are common in surgical patients, especially those with indwelling urinary catheters. Diagnosis is made by dipstick and urine culture (CSU), along with signs of raised inflammatory markers. Treatment involves antibiotics to cover hospital-acquired organisms.
120
What is the mechanism of action of suxamethonium?
Suxamethonium is a depolarising neuromuscular blocker that inhibits the action of acetylcholine at the neuromuscular junction.
121
How is suxamethonium metabolized?
Suxamethonium is degraded by plasma cholinesterase and acetylcholinesterase. However, its metabolism can be affected by the lack of acetylcholinesterase.
122
What are the characteristics of suxamethonium compared to other muscle relaxants?
Suxamethonium has the fastest onset and shortest duration of action among all muscle relaxants. It also produces generalised muscular contraction before inducing paralysis.
123
What are the adverse effects of suxamethonium?
Adverse effects of suxamethonium include hyperkalaemia and malignant hyperthermia.
124
What type of neuromuscular blocking drug is atracurium?
Atracurium is a non-depolarising neuromuscular blocking drug.
125
What is the usual duration of action for atracurium?
The usual duration of action for atracurium is 30-45 minutes.
126
What are the potential side effects of atracurium?
Administration of atracurium may cause generalised histamine release, leading to facial flushing, tachycardia, and hypotension.
127
How is atracurium metabolized?
Atracurium is not excreted by the liver or kidney. Instead, it is broken down in tissues by hydrolysis.
128
Which drug can reverse the effects of atracurium?
The effects of atracurium can be reversed by neostigmine.
129
What type of neuromuscular blocking drug is vecuronium?
Vecuronium is a non-depolarising neuromuscular blocking drug.
130
What is the approximate duration of action for vecuronium?
The duration of action for vecuronium is approximately 30-40 minutes.
131
How is vecuronium metabolized and how can it be affected?
Vecuronium is degraded by the liver and kidney. Its effects may be prolonged in the presence of organ dysfunction.
132
Which drug can reverse the effects of vecuronium?
The effects of vecuronium can be reversed by neostigmine.
133
What type of neuromuscular blocking drug is pancuronium?
Pancuronium is a non-depolarising neuromuscular blocker.
134
What is the onset of action for pancuronium?
The onset of action for pancuronium is approximately 2-3 minutes.
135
What is the duration of action for pancuronium?
The duration of action for pancuronium can be up to 2 hours.
136
Can the effects of pancuronium be reversed?
The effects of pancuronium can be partially reversed using drugs such as neostigmine.
137
What is the American Society of Anesthesiologists (ASA) physical status scoring system?
The ASA physical status scoring system is a classification system used to assess the overall health and well-being of a patient before surgery.
138
What does ASA grade 1 indicate?
ASA grade 1 indicates that the patient has no organic physiological, biochemical, or psychiatric disturbance. The surgical pathology is localized and has not caused any systemic disruption.
139
What does ASA grade 2 indicate?
ASA grade 2 indicates that the patient has mild or moderate systemic disruption, either caused by the surgical disease process or underlying pre-existing disease.
140
What does ASA grade 3 indicate?
ASA grade 3 indicates that the patient has severe systemic disruption, either caused by the surgical pathology or pre-existing disease.
141
What does ASA grade 4 indicate?
ASA grade 4 indicates that the patient has a severe systemic disease that poses a constant threat to life.
142
What are the commonly used intravenous fluids in intraoperative fluid management?
The commonly used intravenous fluids in intraoperative fluid management include plasma, 0.9% saline, dextrose/saline, and Hartmans solution.
142
Atropine
Atropine is a muscarinic receptor antagonist (competitive antagonist for the
muscarinic acetylcholine receptor). It therefore inhibits parasympathetic activity.It
was traditionally used as a premedication for anaesthesia because it reduced
bronchial secretions, salivary secretions and bradycardia from increased vagal
tone on anaesthetic induction. Modern anaesthetic techniques have reduced the
need for routine use of this drug. Its other effects include urinary retention and
pupillary dilatation.
143
What are the composition levels of sodium, potassium, chloride, bicarbonate, and lactate in plasma?
The composition levels of sodium, potassium, chloride, bicarbonate, and lactate in plasma are within the ranges of 137-147 mmol for sodium, 4-5.5 mmol for potassium, 95-105 mmol for chloride, and 22-25 mmol for bicarbonate. Lactate is not present in plasma.
143
What does ASA grade 5 indicate?
ASA grade 5 indicates that the patient is in a moribund state and will not survive without surgery.
144
What is the composition of 0.9% saline?
0.9% saline contains 153 mmol of sodium and 154 mmol of chloride.
145
What is the composition of dextrose/saline?
Dextrose/saline contains 30.6 mmol of sodium and 30.6 mmol of chloride.
146
What is the composition of Hartmans solution?
Hartmans solution contains 130 mmol of sodium, 4 mmol of potassium, 110 mmol of chloride, and 28 mmol of lactate.
147
What is the current approach to fluid administration during surgery?
A tailored approach to fluid administration is now practiced, with greater usage of cardiac output monitors to provide goal-directed fluid therapy. There is also an emphasis on fluid restriction in enhanced recovery programs.
148
What does POPS stand for?
Proactive care of older people undergoing surgery
149
What is an important component of POPS?
Comprehensive geriatric assessment
150
What are the main predictors of complications in older surgical patients?
Co-morbidities, cardiac disease, and reduced functional capacity
150
What is the key to preventing adverse postoperative outcomes in older patients?
Preoperative assessment
151
What risk factors should be screened for in older surgical patients?
Low albumin levels (<30) and co-morbidities
152
What are some potential outcomes of implementing POPS?
Fewer postoperative medical complications and reduced length of stay by 4.5 days
153
What is the recommended preparation for elective surgery cases?
For elective surgery cases, it is recommended to consider a pre-admission clinic to address medical issues. Blood tests including FBC, U+E, LFT's, clotting, and Group and Save should be conducted. Urine analysis, pregnancy test, and sickle cell test should also be performed. Additionally, an ECG and chest x-ray may be required. The specific tests will depend on the proposed procedure and the patient's fitness. Risk factors for deep vein thrombosis should be assessed, and a thromboprophylaxis plan should be formulated.
154
What should be considered for diabetic patients undergoing surgery?
Diabetic patients have a higher risk of complications. Poorly controlled diabetes increases the risk of wound infections. Patients with diet or tablet-controlled diabetes may have their medication omitted, and blood glucose levels should be regularly checked. Diabetics who are poorly controlled or who take insulin may require an intravenous sliding scale. Potassium supplementation should also be given. Diabetic cases should be prioritized for surgery.
155
What should be done for emergency surgery cases?
For emergency surgery cases, the patient should be stabilized and resuscitated if necessary. The need for antibiotics should be assessed, and their administration should be determined. The blood bank should be informed if major procedures are planned, especially when coagulopathies are present or anticipated. Consent and information should be provided to the patient's relatives.
156
What special preparations may be required for certain surgical procedures?
Certain surgical procedures may require special preparations. Thyroid surgery may require a vocal cord check. For parathyroid surgery, methylene blue may be considered to identify the gland. Sentinel node biopsy may involve using a radioactive marker or patent blue dye. Surgery involving the thoracic duct may require the administration of cream. Pheochromocytoma surgery may require alpha and beta blockade. Surgery for carcinoid tumors may require covering with octreotide. Colorectal cases, especially left-sided surgery, may require bowel preparation. For thyrotoxicosis, lugols iodine or medical therapy may be necessary.
157
How should tourniquets be applied and monitored?
Correct application and monitoring, typically using a pressure monitoring system.
157
What is the purpose of using tourniquets during surgery?
Minimize blood loss and ensure a clear operative field.
158
What are the systemic effects of tourniquet inflation?
Increased BP, CVP, systemic vascular resistance, induced hypercoagulable state, slow increase in core temperature.
158
What are the systemic effects of tourniquet deflation?
Fall in BP, CVP, systemic vascular resistance, increased end tidal carbon dioxide, enhanced fibrinolysis, fall in core temperature, raised serum potassium and lactate levels.
159
What are the absolute contraindications for using tourniquets?
AV fistula, severe peripheral vascular disease, previous vascular surgery, bone fracture or thrombosis at the site.
160
What are the relative contraindications for using tourniquets?
Sickle cell disease, history of thromboembolic events, skin grafts, localized infection, lymphedema.
161
What are the potential local complications of tourniquet use?
Skin damage, muscle damage (rarely compartment syndrome), vessel damage, neuropraxia.
162
How often should weight be monitored according to NICE guidelines?
Weight should be monitored daily if there are concerns about fluid balance. Otherwise, it should be monitored weekly, gradually reducing to monthly.
163
When should BMI be measured according to NICE guidelines?
BMI should be measured at the start of feeding and then monthly.
164
What are the alternatives for obtaining weight if it cannot be measured?
If weight cannot be obtained, mid-arm circumference or triceps skinfold thickness can be measured monthly.
165
How often should electrolyte levels be monitored according to NICE guidelines?
Electrolyte levels should be monitored daily until they are stable. Once stable, they should be monitored once or twice a week.
166
Which laboratory tests should be conducted weekly if the patient's condition is stable?
If the patient's condition is stable, weekly laboratory tests should include glucose, phosphate, magnesium, liver function tests (LFTs), calcium, albumin, full blood count (FBC), and mean corpuscular volume (MCV) levels.
167
How often should iron and ferritin levels be monitored according to NICE guidelines?
Iron and ferritin levels should be monitored every 3-6 months. If the patient is on a home parenteral regimen, manganese levels should also be monitored.
168
How often should vitamin D levels be monitored according to NICE guidelines?
Vitamin D levels should be monitored every 6 months.
168
How often should Zn, Folate, B12, and Cu levels be monitored if the patient's condition is stable?
If the patient's condition is stable, Zn, Folate, B12, and Cu levels should be monitored every 2-4 weeks.
169
When should bone densitometry be conducted according to NICE guidelines?
Bone densitometry should be conducted initially when starting home parenteral nutrition and then every 2 years.
170
What is aortic dissection?
Aortic dissection occurs when there is a flap or filling defect within the aortic intima, causing blood to track into the medial layer and create a false lumen. It is most commonly found in the ascending aorta or just distal to the left subclavian artery.
171
What are the common symptoms of aortic dissection?
Patients with aortic dissection typically present with a tearing intrascapular pain, which may resemble the pain of a myocardial infarction.
172
How is aortic dissection diagnosed?
A chest X-ray showing a widened mediastinum may suggest aortic dissection, but confirmation of the diagnosis is usually made using CT angiography.
173
How is aortic dissection classified in the Stanford classification system?
In the Stanford classification system, aortic dissection is classified into Type A lesions (with a proximal origin) and Type B lesions (commencing distal to the left subclavian).
174
What is the preferred treatment for proximal (Type A) aortic dissection?
Proximal (Type A) aortic dissections are usually treated surgically.
175
What is the preferred management for distal (Type B) aortic dissection?
Distal (Type B) aortic dissections are usually managed non-operatively.
176
What are the common symptoms of pulmonary embolism?
Pulmonary embolism typically presents with sudden onset chest pain, haemoptysis, hypoxia, and small pleural effusions may be present. Most patients will have an underlying deep vein thrombosis.
177
How is pulmonary embolism diagnosed?
Diagnosis of pulmonary embolism is usually confirmed through the use of CT pulmonary angiography.
178
What is the treatment for pulmonary embolism?
Treatment for pulmonary embolism involves anticoagulation. In severe cases or in patients with cardiac arrest, thrombolysis may be considered.
179
What are the typical symptoms of myocardial infarction?
Myocardial infarction is traditionally described as a sudden onset of central, crushing chest pain that may radiate into the neck and down the left arm. Autonomic dysfunction may also be present. Symptoms may be atypical in the elderly and those with diabetes.
180
How is myocardial infarction diagnosed?
Diagnosis of myocardial infarction is made through the identification of new and usually dynamic ECG changes, along with cardiac enzyme changes. Inferior and anterior infarcts may be distinguished by specific ECG changes.
181
What are the treatment options for myocardial infarction?
Treatment for myocardial infarction involves oral antiplatelet agents, primary coronary angioplasty, and/or thrombolysis.
182
What are the common symptoms of a perforated peptic ulcer?
Patients with a perforated peptic ulcer usually experience a sudden onset of epigastric abdominal pain, which may be followed by generalized abdominal pain. Gastric ulcers may have worsened pain immediately after eating.
183
How is a perforated peptic ulcer diagnosed?
Diagnosis of a perforated peptic ulcer may be made with an erect chest x-ray, which may show a small amount of free intra-abdominal air.
184
What is the treatment for a perforated peptic ulcer?
Treatment for a perforated peptic ulcer usually involves a laparotomy. Small defects may be excised and overlaid with an omental patch, while larger defects are best managed with a partial gastrectomy.
185
What is Boerhaave's syndrome?
Boerhaave's syndrome is the spontaneous rupture of the esophagus, usually resulting from repeated episodes of vomiting. The rupture is typically distally sited and on the left side.
186
What are the symptoms of Boerhaave's syndrome?
Patients with Boerhaave's syndrome often have a history of sudden onset of severe chest pain, which may occur after severe vomiting. Severe sepsis can occur as a result of mediastinitis.
187
How is Boerhaave's syndrome diagnosed?
Diagnosis of Boerhaave's syndrome is done through CT contrast swallow.
188
What is the treatment for Boerhaave's syndrome?
Treatment for Boerhaave's syndrome involves thoracotomy and lavage. If treated within 12 hours of onset, primary repair is usually feasible. Delayed surgery beyond 12 hours may involve the insertion of a T tube to create a controlled fistula between the esophagus and skin. Delays beyond 24 hours are associated with a very high mortality rate.
189
What happens to the sympathetic nervous system during surgery?
The sympathetic nervous system releases noradrenaline from sympathetic nerves and adrenaline from the adrenal medulla.
190
What are the effects of sympathetic nervous system activation during surgery?
Blood is diverted from the skin and visceral organs, bronchodilation occurs, intestinal motility is reduced, and there is an increase in glucagon and glycogenolysis. Additionally, heart rate and myocardial contractility are increased.
191
What is the acute phase response during surgery?
During surgery, the release of TNF-α, IL-1, IL-2, IL-6, interferon, and prostaglandins leads to the acute phase response.
192
What can excessive cytokines released during surgery cause?
Excessive cytokines may cause systemic inflammatory response syndrome (SIRS).
193
What is the endocrine response during surgery?
The hypothalamus, pituitary, adrenal axis is activated during surgery, leading to an increase in ACTH and cortisol production.
194
What are the effects of increased cortisol production during surgery?
Increased cortisol production during surgery results in protein breakdown and elevated blood glucose levels.
195
What are the effects of aldosterone during surgery?
Aldosterone increases sodium re-absorption.
196
What are the effects of vasopressin during surgery?
Vasopressin increases water re-absorption and causes vasoconstriction.
197
What role does the vascular endothelium play during surgery?
The vascular endothelium produces nitric oxide, which leads to vasodilation.
198
What is the role of platelet activating factor during surgery?
Platelet activating factor enhances the cytokine response.
199
What are the effects of prostaglandins during surgery?
Prostaglandins induce vasodilation and platelet aggregation.
199
What are packed red cells used for?
Transfusion in chronic anemia and cases where infusion of large volumes of fluid may result in cardiovascular compromise.
200
How is platelet-rich plasma obtained?
By low-speed centrifugation.
201
When is platelet concentrate administered?
To patients with thrombocytopenia.
202
What does fresh frozen plasma contain?
Clotting factors, albumin, and immunoglobulin.
203
When is fresh frozen plasma usually used?
In correcting clotting deficiencies in patients with hepatic synthetic failure who are due to undergo surgery.
204
What is cryoprecipitate?
A rich source of Factor VIII and fibrinogen, formed from the supernatant of fresh frozen plasma.
205
What is SAG-Mannitol Blood?
Blood where all plasma is removed from a blood unit and substituted with sodium chloride, adenine, anhydrous glucose, and mannitol.
206
How many units of SAG-M Blood can be administered?
Up to 4 units. Thereafter, whole blood is preferred.
207
Can platelets and fresh frozen plasma be ABO incompatible in adults?
No, they cannot be ABO incompatible in adults.
208
What is the target of Adalimumab, Infliximab, and Etanercept?
TNF alpha inhibitor.
209
Which blood components require cross-matching?
Packed red cells and whole blood.
210
What are the uses of Adalimumab, Infliximab, and Etanercept?
Crohn's disease and rheumatoid disease.
211
What is the target of Bevacizumab?
Anti VEGF vascular endothelial growth factor (anti-angiogenic).
212
What are the uses of Bevacizumab?
Colorectal cancer, renal cancer, and glioblastoma.
213
What is the target of Trastuzumab?
HER receptor.
214
What is the use of Trastuzumab?
Breast cancer.
215
What is the target of Imatinib?
Tyrosine kinase inhibitor.
216
What are the uses of Imatinib?
Gastrointestinal stromal tumors and chronic myeloid leukemia.
217
What is the target of Basiliximab?
IL2 binding site.
218
What is the use of Basiliximab?
Renal transplants.
219
What is the target of Cetuximab?
Epidermal growth factor inhibitor.
220
What is the use of Cetuximab?
EGF positive colorectal cancers.
221
What is endoscopy?
A procedure that allows the internal visualization of the viscera.
222
What are some commonly performed endoscopic procedures?
Gastroscopy, colonoscopy, cystoscopy, ERCP, and bronchoscopy.
223
How are most endoscopes designed?
They are flexible instruments with three channels and a video chip with an illumination source at the end.
224
What are the channels in endoscopes used for?
Suction, irrigation, and instrumentation.
225
Do all endoscopic procedures require patient sedation?
No, some procedures call for patient sedation while others do not.
225
What is the purpose of the control stack in flexible endoscopes?
It allows the tip of the instrument to be manipulated.
226
Where should endoscopies be performed?
In dedicated units with appropriately trained staff and full resuscitation facilities available.
227
What is the preparation for ERCP?
Clotting, antibiotics, and Vitamin K if jaundiced.
228
What is the preparation for diagnostic OGD?
Nil by mouth for 6 hours.
229
What is the preparation for flexible sigmoidoscopy?
Phosphate enema 30 minutes before the procedure.
230
What is the preparation for colonoscopy?
Check U+E and if normal, prescribe oral purgatives (e.g., picolax).
